Immunizations are among the most effective and cost-effective prevention interventions available. A missed opportunity (MO) for vaccination occurs when children who are eligible for one or more immunizations visit health care providers but are not vaccinated. MOs are almost always caused by underlying medical errors, and they are a major factor contributing to under-immunization and delay in age-appropriate immunization in children, leaving these children - andtheir household andcommunity contacts - vulnerable to avariety of serious, preventable communicable diseases. Research has shown that 13 to 60% of the time spent overdue for some immunizations during the first two years of life is due to missed opportunities, with higher percentages for children living in poverty. Thus, MOs contribute not only to poor health outcomes but also to health disparities along socioeconomic and racial-cultural lines. Lower rates of immunization also serve as an indicator of inadequate receipt of other preventative health care services. The purpose of this proposal is to intervene with providers, parents, schools and daycares to improve immunization completion rates by decreasing errors associated with missed opportunities for vaccination. The specific aims of this project are: 1. To implement provider education and process refinement interventions and evaluate their effectiveness in decreasing immunization errors including missed opportunities; 2. To implement parental education and case management interventions and evaluate their effectiveness in decreasing missed opportunities and delays in immunization and increasing healthcare utilization. 3. To implement a set of community intervention activities to reduce immunization disparities and increase immunization rates . 4. To develop sustainable and transferable interventions for reducing racial disparities in immunizations